PRO AUDIO
Matt

Matt
March 14, 2014

JBL Hearing the Truth: Design

In the final installment of our JBL Hearing the Truth series focuses on the engineers and the architecture behind the design of the M2 studio monitors. These are the monitors that inspired the JBL LSR 3 Series studio monitors and they share the same transducer and waveguide technology, but at a fraction of the cost. JBL Professional president Bryan Bradley hosts this collection of interviews with the engineers responsible for designing and testing the components that make up their studio monitors. The interesting thing to note about JBL and their speaker design is that they craft all of their parts in house. While other speaker companies shop for off the shelf parts to design their systems, JBL has trained specialists and audio engineers manufacturing their own parts which makes JBL’s speaker technology so unique.

In addition to the company’s unique speaker design, their is also a level of quality that comes from in house craftsmanship. By using technologies like 3D modeling and printing, their engineers can design parts to fit into their systems with a level of expediency that is leaps and bounds beyond how these parts used to be designed and tested. This speaks to the care and attention that is paid to their speaker design from a desktop speaker all the way up to their massive line array systems. If you have seen all of the JBL Hearing the Truth videos up to this point I expect that you either own a pair of LSR 3 Series monitors or are in the midst of purchasing them after reading this. I can fully relate. It took me actually hearing the 3 Series to fully appreciate what I was missing from my previous studio monitors. The JBL LSR 3 Series monitors are some of the most affordable studio monitors for what they can achieve sonically and you will not be disappointed when you get them in your own home studio.

If you haven’t seen the previous videos in our JBL Hearing the Truth series, be sure to head on over to our YouTube channel where we have made a playlist for you to watch. If you are interested in picking up the JBL LSR 305, JBL LSR308, or any other JBL product, be sure to head on over to UniqueSquared.com.

SLAM!!

Transcript

Hi my name is Bryan Bradley. I’m the president at JBL Professional. One of the first things I found when I got here was this M2 technology that recently came out in April and it’s amazing. When I first saw it, the first thought that came to my head is, “This is great but this is a $20,000 system. How can we take this JBL technology and bring it downstream so that a lot of people can get the benefits of the waveguide that Charles Sprinkle developed.” I challenged the team right off the bat, within a month of coming on board, to find us a way to do that. What they came up with was the 3 Series. The 305 and the 308 and it’s impressive. Hi I’m Peter Chaikin. I’m the senior manager of recording and broadcast marketing for JBL Professional and that’s the segment responsible for studio monitors. The objective is, yeah its gotta sound good in your control room, in the place where you are creating content whether its music or audio for TV, or broadcast. Its got to sound good there. But the real objective is, that piece of content that you’re creating has to sound good everywhere else. So at JBL we’ve spent our entire history examining that phenomenon and that problem. What we’ve come up with are a set of measurements and technologies that allow us to create a speaker that’s going to be a very reliable reference for you. One of those technologies is what we call waveguide. This is the device that surrounds the high frequency driver in our M2 Studio Monitor and it’s a big interesting looking thing. What this does basically is it insures that what the speaker sends to the wall ceiling and floor is very very neutral and it makes sure that all of the beautiful high frequency that the fabulous D2 driver that we’re using that all that high frequency makes it out into the room. Now that we have this waveguide technology, we were able to apply it to a very very affordable studio monitor and that’s called the 3 series. What a waveguide does is it controls the dispersion, it controls the radiation from the tweeter so that it matches the radiation pattern or the sound pattern from the woofer at the cross over frequency and provides us a continuity of directivity across the frequency range. Being able to control directivity not just in a vertical and horizontal but all the way around, allows us to have very tight control of that but it also fixes some of the directivity anomalies that we’ve seen on previous horns making this horn and this waveguide geometry not just on the reference monitor but also on the 3 Series monitor be seamless in the acoustic transition between the low frequency driver and the high frequency driver. These speakers aren’t designed for a living room. These are designed for a studio. The critical performance element here is accuracy. A studio engineer needs to hear what’s in their mix. They need to hear frequency response problems. They need to hear the spatial elements of their mix. They need to hear the sense of envelopment. They need to hear mic placement. These are things that can be delivered if you get your directivity correct, if you get the frequency response correct, if you get your time domain response correct, and this can be done even at the 3 Series level all the way up to the M2 reference monitor. If you take a speaker with bad directivity index, you cannot predict how that loud speaker is going to act in different rooms. So as a result of that it’s hard to get continuity between two different environments. When you get the directivity index of a loud speaker correct, then it’s going to matter much less what environment and what room it’s in. One of the great things about the 3 Series compared to similar product is it’s a JBL product start to finish. We’re not out shopping for off the shelf parts. Our engineers are designing them. Ok so my name is Alex Voishvillo and I’m a senior manager of transducer engineering. We have a liberty of designing transducers for particular applications. Custom made transducers which our customers typically don’t deal with. They just buy something off shelf. Plus of course it’s cheaper. It’s much more cost effective. The idea was to take two of these diaphragms and combine them into single unit. In other words two diaphragms here, two phasing plugs. Acoustical signal comes out and goes inwards and then it’s radiated. In other words two coils do the job of one coil. So we need less input power for the same sound pressure level. So this one is used in M2 Studio Monitor. This is another example. This is prototype of 2 inch voice coil phasing plugs which is made on our rapid prototyping machine. In other words we create three dimensional files, load into the machine, into a 3D printer, and next day, it runs overnight, and we have parts. Ok in the real world when we start doing the modeling for the real models we are doing on a computer on a CAT program. We are making the files and we transfer these files to a prototyping machine which we have opportunity to speed up our production, speed up our development time almost three, four times. What it does, as soon as we tested this part in a system, if we need to modify something it’s going to take me maybe a day to modify and then if we need another, we put another in the machine. I am Ralph Hyde. I am the principal transducer engineer for JBL Professional. I shouldn’t say “the” because there are several engineers here that work on transducers. High SPL, flat frequency response, low distortion, so those are the challenges we face. We get to custom design a woofer for what specific purpose we want. I think the primary reason is I don’t know where we can buy a speaker which is as good as the one’s we design and make ourselves. I just don’t know where to go get one. This is the 8 inch woofer from the old LSR 28. This one is also a differential drive in that you have a gap here and a gap here, but in this case this is the magnet here and here. It’s a ceramic magnet. It’s on the outside. Again the flux path goes around here. There have to be larger steel pieces because of the larger magnet and everything. But this is a good example of a differential drive speaker with a ceramic magnet. This one was optimized for studio monitors so it has three shorting rings in it. There’s one here, there’s one here, and there’s one right here. So there was a lot of effort here in keeping distortion low. This one also, instead of having just two coils, it has a third coil which you may be able to see right here and this is a breaking coil. It’s just shorted to itself. It’s not wired to the outside world. But if you get too much motion and that center coil moves up into the gaps, it induces a current in the coil, dissipated as heat, provides a breaking force. So it keeps the cone from going out of control. From going farther than you want it to go. What is patented here is the combination of the shorting rings with differential drive and there are multiple patents on this speaker. One of the things I love most about this job is the amazing experiences we get to have that JBL is bringing to its employees. We had Jeff Emerick in the other day to listen to the M2s and I mean talk about an amazing experience. Sitting there with the engineer for the Beatles, listening to the mono masters of the Abbey Road recordings through the M2s. I mean it’s incredible and to watch his reaction was amazing and what was even cooler was he had a similar reaction when we played for him the 3 Series which is an affordable monitor that everyone can enjoy. That’s amazing. Another great thing about JBL is the fact that through all of these decades it continues to remain relevant. The M2s have 8 patents on them. Derivatives of those are available on the 3 Series. The fact that this company was an integral part of Woodstock and was essentially one of the inventors of transducer technology and the fact that we can continue to reinvent that is amazing. We have the D2 driver. Came out 2 years ago. That’s a whole new patent on a product that hasn’t had a new patent on it in 60 years. To be able to design something like that, develop something like that today and remain relevant, not just trade on a brand and the color orange for decades, that’s amazing. I love running a company where the brand is continually evolving and the people are continually redeveloping and improving on and already existing high quality product. That’s a fun thing to be a part of.